使用Spring容器在非spring对象上调用方法，以允许参数接线吗？

Question

I have an object that is created outside of the container. This object has one method accept(...) . Note that this is not an interface method, as the number and the type of the parameters are unknown.

Anyhow, I have also the Method of the accept() method.

I would like to execute this method within the Spring application context, allowing Spring to auto-wire method parameters before running the method.

Example:

public class MyCmd {
    public long accept(@AutoWire MyService service) {
    ...
    }
}

and later:

MyCmd cmd = new MyCmd();     // no spring here!
magicRunner.invoke(cmd);     // magic here

Here I want to be able to run accept() , but to let the Spring to inject the MyService as an argument for the method.

Is there anything like this in Spring? Or I have to do all this manually?

Answer 1

I think that this is hardly doable to mix reflection and Spring autowiring through method arguments, but still there is an approach that looks equivalent to what you are trying to achieve (if I understand it properly).

MyCmd can be registered with "prototype" scope in the AplicationContext . It will be autowired with other existing Spring beans, but a new instance will be returned each time you look for it in the context:

@Component
@Scope(value = ConfigurableBeanFactory.SCOPE_PROTOTYPE)
@Data
public class MyCmd {

  @Autowired
  private MyService myService;

  public long accept() {
    // ...
  }

}

Now, when you need to use MyCmd :

  @Autowired
  private ApplicationContext applicationContext;

  public void doMyThings() {
    MyCmd myCmd = applicationContext.getBean(MyCmd.class);
    // myCmd is a new ref each time, myService is autowired inside
    magicRunner.invoke(cmd);  
  }

Answer 2

Yes you can use @Configurable to dependency inject domain objects in Spring employing AspectJ.

Here's the documentation on @Configurable.

Example with constructor DI:

@Configurable
public class MyCmd {

    @Autowired
    public MyCmd(MyService service) {
      ...
    }
}

But beware: from that point on this is a Spring-managed bean so you cannot instantiate it as:

MyCmd cmd = new MyCmd();

But rather you'll have to Dependency Inject it as usual.